While the 10-year window is in line with Microsoft's previous OS releases, Monday's update brings clarification to a question that Microsoft had been previously vague about. In January, Terry Myerson, executive vice president of the Windows and Devices Group at Microsoft, suggested that the traditional 10-year support plan might be changing.

"Once a device is upgraded to Windows 10, we will be keeping it current for the supported lifetime of the device," Myerson said at the time.

Monday's update to the fact sheet appears to put that question to rest, as does a recent comment from a Microsoft spokesperson to Computerworld. "The traditional 10-year support lifecycle applies to all SKUs [stock-keeping units]," Microsoft said in an e-mailed statement to Computerworld on Friday.

Microsoft's lifecycle fact sheet also stated that a machine running Windows 10 will only be eligible for support if it is running the latest updates. The company designates updates as including "new features, fixes (security and/or non-security), or a combination of both." Furthermore, support could be lost by devices that are incompatible with current or future Windows 10 updates and features.

For those who may not be eligible for the free Windows 10 upgrade program, the OS popped up on Amazon.com late last week ahead of its official July 29 release. The online retailer started taking preorders for both the Windows 10 Home and Windows 10 Pro versions. Both versions will start shipping on Aug. 30 and arrive on USB flash devices. The Home version will cost $119.99, while the Pro version has a price tag of $199.99.